1. Field of the Invention
The invention relates to a vehicle operation pedal and in particular to a structure for integrally fixing a pedal sheet to a lower end portion of a pedal arm.
2. Description of the Related Art
A vehicle operation pedal that includes (a) a pedal arm disposed on a pedal support so that the pedal arm is pivotable about a support axis, the pedal support being fixed to a vehicle and (b) a pedal sheet to be depressed by a driver, the pedal sheet being integrally attached to a lower end portion of the pedal arm so as to extend from the pedal arm on both sides in a vehicle width direction, is often used as a brake pedal, an accelerator pedal, or the like. The vehicle operation pedal described in Japanese Patent Application Publication No. 2007-122610 is an example. This pedal arm is formed of a pair of halves having shapes obtained by dividing the pedal arm in the vehicle width direction and the peripheral portions of the pair of halves are integrally welded to obtain a hollow structure. Lower end portions of the pair of halves, to which the pedal sheet is fixed, are enlarged apart from each other in the vehicle width direction and the pair of halves are bent inward from the enlarged end portions at substantially right angle to form a sheet attachment portion. The pedal sheet is integrally fixed to the sheet attachment portions by welding, for example.
However, in such a vehicle operation pedal, the welds are close to a center portion of the pedal sheet and therefore, during an offset depression, in which one end portion of the pedal sheet is depressed, a large pulling-off force is applied to the welds. For example, FIG. 6B is a sectional view corresponding to the VIB-VIB section of FIG. 6A and shows a case where sheet attachment portions 60a and 60b are inwardly provided at lower end portions of the pair of halves 32 and 34 of the operation pedal 14 and end edges of the sheet attachment portions 60a and 60b are integrally welded to the pedal sheet 18 by arc welding or the like. When a depression force F is applied to one end E of the pedal sheet 18, relatively large pulling-off forces La and Lb are applied to the welds W2a and W2b with the point P serving as a fulcrum. Thus, a relatively high joint strength is required and costs for welding become high.